Fluid dispensing or infusion devices exist in a variety of forms, from simple gravity feed systems to complex electronic control systems, typically which utilize sophisticated features for precise control and flexibility when delivering fluids through a syringe in, e.g., medical applications. Many systems use a stepper motor to advance a lead screw in precise increments as controlled by a microprocessor, which in turn advances a plunger to deliver the fluid out of the syringe container.
Traditionally, some dispensing devices have included spring mechanisms whereby a user can apply a force to a syringe plunger. In some devices, the force applied to the syringe depends on the size of the syringe. One version of a mechanical syringe-based fluid dispensing system includes one or more constant force coil springs as the means by which fluid is driven out of the syringe container. Examples of such systems are taught in, e.g., U.S. Pat. Nos. 4,430,079; 4,681,566; 4,863,429; 5,380,287 and 6,278,892.
What is needed, however, is a system that can reliably and simply provide specific material delivery profiles, for example, by sequentially providing two different forces to dispense material from a container. For example, when introducing materials or fluids into certain medical implants such as balloons or inflatable grafts for treating, e.g., aortic aneurysms, it is desirable to have improved methods, devices, and systems that are capable of accurately, safely and reliably delivering such materials or fluids therein. It is further desirable to have improved approaches for delivering curable materials through a catheter to such an implant under a specific force profile, such that the material can appropriately cure and thus the potential of malfunction, disfiguration, or over inflation of the graft due to improper delivery of the curable material is minimized.